Manufacture of inflatable membranes

ABSTRACT

A method includes applying a transferrable material to an outer surface of a casting plate to form a pattern on the outer surface of the casting plate. After applying of the transferrable material, a composite material is applied to the outer surface of the casting plate to form an inflatable membrane. The composite material covers at least a portion of the pattern and includes a florescent material and a pigment material. The inflatable membrane is cured to allow removal of the inflatable membrane from the casting plate. The inflatable membrane has an inner surface having the pattern detectable upon receiving of light causing the fluorescing material to emit florescent light.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/436,340, which is entitled “MANUFACTURE OFINFLATABLE MEMBRANES,” and filed on Dec. 19, 2016, the disclosure ofwhich is incorporated herein by reference for all purposes.

TECHNICAL FIELD

The subject matter described herein relates to systems, methods, andcomputer programs for the manufacturing of inflatable membranes.

SUMMARY

In one aspect, a method can include applying a transferrable material toan outer surface of a casting plate to form a pattern on the outersurface of the casting plate. After applying of the transferrablematerial, a composite material is applied to the outer surface of thecasting plate to form an inflatable membrane. The composite materialcovers at least a portion of the pattern and includes a florescentmaterial and a pigment material. The inflatable membrane is cured toallow removal of the inflatable membrane from the casting plate. Theinflatable membrane has an inner surface having the pattern detectableupon receiving of light causing the fluorescing material to emitflorescent light.

In some variations one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The transferrable material may be applied by ahypodermic needle, painting with a brush, spraying, printing from alaser jet printer, printing from a pad printer, and/or etching anddipping. The composite material may be applied by dipping the castingplate with the transferrable material into the composite material.

In another aspect the method may include applying a first layer of afiducial material to an outer surface of a casting plate, the fiducialmaterial comprising fiducial markers suspended in the fiducial material;applying a second layer of a composite material to the first layer toform an inflatable membrane, the composite material comprising aflorescent material and a pigment material; and curing the inflatablemembrane to allow removal of the inflatable membrane from the castingplate, the inflatable membrane comprising an inner surface having thefiducial markers detectable upon receiving of light causing thefluorescing material to emit florescent light.

In some variations one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The method of claim 4, wherein the fiducialmarkers have a particle size of 50 microns to 400 microns. The firstlayer may be a clear layer without pigment material and the florescentmaterial. The second layer ma include the fluorescent material but notthe pigment material. The third layer may include the pigment materialbut not the fluorescent material. The pigment material may be selectedto vary the optical and/or mechanical properties of the membrane. Thefirst layer, the second layer, and the third layer may be applied bydipping the casting plate into the fiducial material, the compositematerial, or the pigment material. An aperture may be formed in a distalend of the inflatable membrane. A transparent material may be applied tospan the aperture to form a window in the distal end of the inflatablemembrane. The method may selectively applying the first layer and thesecond layer to the outer surface of the casting plate, without applyingthe first layer and the second layer to the distal end of the castingplate, to form the aperture in the distal end.

In an interrelated aspect, an apparatus includes an inflatable membranehaving a pattern layer, a fluorescent layer, and a window. The patternlayer has an inner surface and an outer surface. The pattern layer has apattern on the inner surface of the pattern layer and at least a portionof the pattern layer formed by a casting plate configured to create thefiducial markers. The fluorescent layer has an inner surface and anouter surface. The inner surface of the fluorescent layer abuts theouter surface of the pattern layer and includes a fluorescent materialwhich, upon receiving of light, causes the florescent material to emitfluorescent light and causing the pattern to be detectable by adetector. The window includes a transparent material that spans anaperture formed in a distal end of the inflatable membrane.

In some variations one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The fluorescent layer may include a pigmentmaterial. The pattern may include a grid formed by the transferrablematerial and the pattern may include spots formed by the transferrablematerial. The inflatable membrane may include a pigmented layer havingan inner surface and an outer surface. The inner surface of thepigmented layer may abut the outer surface of the fluorescent layer andcomprising a pigment material. The fluorescent layer may include amatrix material that includes the fluorescent material and the pigmentmaterial. The fluorescent material may be a fluorescent dye and thepigment material is a carbon black. The inflatable membrane may beconical in shape such that the inflatable membrane is insertable intothe ear of a person. The inflatable membrane may also include anaperture formed in a distal end of the inflatable membrane. The windowcan include a transparent material spanning the aperture to allow lightto pass through the distal end.

In an interrelated aspect, an inflatable membrane includes a patternlayer, a fluorescent layer, and a window. The pattern layer has an innersurface and an outer surface. The pattern layer has a random patternformed by fiducial markers suspended in a transparent matrix materialintegrated with the pattern layer and at least a portion of the patternlayer formed by, for example, a casting plate configured to create thefiducial markers. The fluorescent layer has an inner surface and anouter surface. The inner surface of the fluorescent layer abuts theouter surface of the pattern layer and includes a fluorescent materialwhich, upon receiving of light with wavelengths in the excitationwavelength, causes the florescent material to emit fluorescent light ofa different wavelength and causing the pattern to be detectable by adetector. The window includes a transparent material spans an apertureformed in a distal end of the inflatable membrane.

Implementations of the current subject matter can include, but are notlimited to, systems, apparatuses, and methods consistent with thedescriptions provided herein as well as articles that comprise atangibly embodied machine-readable medium operable to cause one or moremachines (e.g., computers, etc.) to result in operations implementingone or more of the described features. Similarly, computer systems arealso contemplated that may include one or more processors and one ormore memories coupled to the one or more processors. A memory, which caninclude a computer-readable storage medium, may include, encode, store,or the like, one or more programs that cause one or more processors toperform one or more of the operations described herein. Computerimplemented methods consistent with one or more implementations of thecurrent subject matter can be implemented by one or more data processorsresiding in a single computing system or across multiple computingsystems. Such multiple computing systems can be connected and canexchange data and/or commands or other instructions or the like via oneor more connections, including but not limited to a connection over anetwork (e.g., the internet, a wireless wide area network, a local areanetwork, a wide area network, a wired network, or the like), via adirect connection between one or more of the multiple computing systems,etc.

The details of one or more variations of the subject matter describedherein are set forth in the accompanying drawings and the descriptionbelow. Other features and advantages of the subject matter describedherein will be apparent from the description and drawings, and from theclaims. While certain features of the currently disclosed subject matterare described for illustrative purposes in relation to particularimplementations, it should be readily understood that such features arenot intended to be limiting. The claims that follow this disclosure areintended to define the scope of the protected subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, show certain aspects of the subject matterdisclosed herein and, together with the description, help explain someof the principles associated with the disclosed implementations. In thedrawings,

FIG. 1 is a diagram illustrating a simplified sectional view of anexemplary inflatable membrane, in accordance with certain aspects of thepresent disclosure;

FIG. 2 is a simplified diagram illustrating a composite material havinga matrix material, a pigment material, and a fluorescent material, inaccordance with certain aspects of the present disclosure;

FIG. 3 is a diagram illustrating an exemplary process of forming theinflatable membrane around a casting plate, in accordance with certainaspects of the present disclosure;

FIG. 4 illustrates applying a transferrable material to an outer surfaceof a casting plate to form a pattern, in accordance with certain aspectsof the present disclosure;

FIG. 5 illustrates applying a composite material to the outer surface ofthe casting plate after the applying of the transferrable material, inaccordance with certain aspects of the present disclosure;

FIG. 6 illustrates forming of the inflatable membrane after removal fromthe composite material, in accordance with certain aspects of thepresent disclosure;

FIG. 7 illustrates an exemplary inflatable membrane after inversion,showing the pattern on the inner surface of the inflatable membrane, inaccordance with certain aspects of the present disclosure;

FIG. 8 is a diagram illustrating a second exemplary process of formingthe inflatable membrane around the casting plate, in accordance withcertain aspects of the present disclosure;

FIG. 9 illustrates a process flow diagram for a representative method ofmaking inflatable membrane material, in accordance with certain aspectsof the present disclosure; and

FIG. 10 illustrates a simplified diagram imaging the interior surface ofthe inflatable membrane through a media that differentially absorbsdifferent wavelengths to determine the shape of an exterior surface ofan object, in accordance with certain aspects of the present disclosure.

DETAILED DESCRIPTION

In certain industrial processes, an interior surface of an object orcavity may be scanned by imaging a pattern of light emitted or reflectedfrom the interior surface. Based on the contours or three-dimensionalshape of the interior surface, the received pattern of light may beinterpreted to reconstruct the shape of the interior surface. To providea surface with analyzable surface features, a deformable membrane may beapplied to the interior surface to closely approximate the shape of theinterior surface. The deformable membrane may include a particularpattern or other features that may facilitate reconstruction of thethree-dimensional shape of the interior surface.

In some implementations, the deformable membrane may be applied to, forexample a cavity, by inflating the deformable membrane until thedeformable membrane closely conforms to at least a portion of theinterior surface of the cavity, such as an ear or other cavity. Othermethods of applying the deformable membrane may be implemented, forexample, spraying, pouring, pressing, molding, or the like, of thedeformable membrane. However, as used herein, and without implying anylack of generality, the deformable membrane will be referred to as aninflatable membrane.

FIG. 1 is a diagram illustrating a simplified sectional view of anexemplary inflatable membrane 100 in accordance with certain aspects ofthe present disclosure. As shown in the implementation of FIG. 1, theinflatable membrane 100 may fill a cavity 105 and closely conform to aninner surface 110 of the cavity. A light source 115 may be introducedinto the cavity 105 to illuminate, with incident light 120, at leastpart of the inflatable membrane 100. The inflatable membrane 100 mayinclude a fluorescing material which may generate fluoresced light 130.The fluoresced light 130 may be received by a detector (here shownintegrated with the light source 115). When imaged through an opticallytuned differentially absorbing medium, the received light can beanalyzed to determine an interior shape of the inflatable membrane 100and hence of the cavity 105.

FIG. 1 also includes an expanded view of a portion of the inflatablemembrane 100. The expanded view illustrates incident light 120 reachingthe inflatable membrane 100. In the example implementation of FIG. 1,the inflatable membrane 100 may be constructed of three layers ofmaterial, though any number or combination of layers may be implemented.One layer may be a fluorescing layer 125 of florescent material may thatlie behind a pattern layer 140, although the pattern layer 125 may belocated right behing the pattern layer 140 as well. The pattern layer140 may include the pattern used to reconstruct the shape of the cavity105. Because the pattern layer 140 may be between the fluorescing layer125 and the detector, the fluoresced light 130 may be partially blockedby the material making the pattern. In another implementation, thematerial making the pattern may not fluoresce, creating a negative imagecorresponding to the pattern. Thus, the fluoresced light 130 may includeinformation about the pattern that may be analyzed to determine theshape of the cavity 105. In some implementations, there may also beanother pigmented layer 145 that may be generally opaque to the incidentlight 120 or the fluoresced light 130. The pigmented layer 145 may beapplied to be between the fluorescing layer 125 and the cavity 105.

In some implementations, the inflatable membrane 100 contains afluorescent material, such as a dye or pigment, which may return animage of fluoresced light 130 when illuminated with, for example,visible blue or UV (ultra-violet) light. The concentration of pigmentmay be configured to be high enough to provide adequate opacificationbut low enough to provide a soft enough material to allow for adequateconformance of small features in the cavity. In other implementations,the inflatable membrane 100 may contain a fluorescent dye that returnsan image when illuminated with white light. Some implementations mayinclude an inflatable membrane 100 that may contain a fluorescent dyethat returns an image when illuminated with light that is not visible tothe naked eye, that is to say light has a wavelength that is outside therange of about 390 to 700 nm. In implementations where the inflatablemembrane 100 contains a fluorescent material that returns an image offluoresced light when illuminated with visible blue light, the membranemay fluoresce red and green light. Alternatively, the inflatablemembrane 100 may fluoresce in any combination of two or morewavelengths, or ranges of wavelengths, of light in response toillumination with blue or white light. In such implementations, theremay be a wavelength, band of wavelengths, multiple wavelengths, ormultiple bands of wavelengths of illuminating light, such that thespectrum of the fluoresced light emitted in response to the illuminatinglight may not change by more than about 0.5% over the length of theinflatable membrane 100. For example, if the inflatable membrane 100fluoresces red and green light in response to illumination with visibleblue light, the ratio of red to green fluoresced light may not vary bymore than about 0.5% over the length of the membrane, more than 1.0%, ormore than 2.0% over the length of the membrane.

The inflatable membrane 100 may be filled with a medium 150 to inflatethe inflatable membrane 100. The medium 150 may, for example, be aliquid, a dissolved gas, a gel, a hydrogel, and/or any combination ofthe four. The medium 150 may include additives dissolved into, orsuspended in, the medium 150 to provide optical properties that may beused with imaging techniques to measure the shape of the interiorsurface of the inflatable membrane 100. These properties may include,for example, selective absorption/attenuation where one or morewavelengths of light are absorbed more than one or more otherwavelengths. To illustrate, medium 150 may include a colored dye,suspension, a luminescent substance, and/or a fluorescent substance(and/or any other material having selective attenuation properties).Moreover, the selective attenuation properties may allow a detector toreceive the selectively attenuated light to determine the shape of,distance to, and/or other properties of the scanned interior surface ofinflatable membrane 100. In implementations where the inflatablemembrane 100 fluoresces red and green light, the medium 150 may be a redfluid that preferentially absorbs the green light. By measuring theamount of attenuation (which is a known function of path length betweenthe emitting surface and the detector), the distance from the surface tothe detector can be determined based on the ratio of intensities at twomeasured wavelengths (shown in FIG. 1 by the arrows having differentlength when reaching the light source/detector 115). The medium 150 mayalso contain a bio-neutralizing, anti-microbial, or anti-oxidizing agentto improve the shelf life of the medium 150 as well as a buffering agentto improve the stability of the medium 150.

FIG. 2 is a simplified diagram illustrating a composite material 200having a matrix material 210, a pigment material 215, and a fluorescentmaterial 220, in accordance with certain aspects of the presentdisclosure. In some implementations, the inflatable membrane 100 mayinclude one or more layers of material. Some implementations may havedifferent types of material comingled in a layer to form a compositelayer.

The inflatable membrane 100 may include, for example, the matrixmaterial 210, the pigment material 215 for opacity, and the fluorescentmaterial 220, such as a pigment or dye. The pigment material may alsoaffect the mechanical properties, such as the stiffness of the membranemay be configured by adjusting the amount of pigment material. All ofthe materials may be selected to be biocompatible and to illicit aslittle reaction from the human body as possible. In some exampleimplementations, this may be considered important because a goal ofusing the inflatable membrane 100 with a 3D scanning system is toimprove comfort for the patient during fabrication of a 3D rendering ormodel of an anatomical cavity. The matrix material 210 may be abiocompatible or bio-inert polymer or mixture of polymers. The pigmentmaterial 215 for opacity may have little cytotoxic, sensitization,and/or irritation activity at the particle sizes and exposure levelsthat are possible when using the inflatable membrane 100.

The inflatable membrane 100 may comprise predominantly the matrixmaterial 210. Correspondingly, the raw materials of the inflatablemembrane 100 may comprise predominantly the matrix material 210 or itsprecursors, as well. The matrix material 210 may be combined as a liquidwith the pigment material 215 for opacity and fluorescent dye duringfabrication. Post-mixing curing, which can include casting, molding,heating, or the addition of further chemicals, may cause the matrixmaterial 210 to transition from a pourable material, to a solid materialwith sufficient elasticity and toughness, as described above, to beuseful in the scenarios described herein, such as multiple inflations atmultiple degrees of inflation (e.g., multiple degrees of pressurizationof the inflatable membrane 100).

In some implementations, the inflatable membrane 100 may have acomposite layer including a matrix material 210 with pigment material215 for opacity and particles of fluorescent material 220 which are notdistinguishable to the naked eye as discrete particles when in theinflatable membrane 100. The inflatable membrane 100 has the pigmentmaterial 215 and fluorescent material 220 embedded in the bulk of thematrix material 210, on the surface of the inflatable membrane 100, orsome combination thereof. For example, the pigment material 215 may beembedded within the matrix material 210 and the fluorescent material 220may be on the surface of the inflatable membrane 100, or the fluorescentmaterial 220 may be embedded in the matrix material 210 and the pigmentmaterial 215 may be on the surface of the inflatable membrane 100.Alternatively or additionally, the matrix material 210 may have both thepigment particles 215 and the fluorescent material 220 embedded in itand additional fluorescent material may be applied to the surface of theinflatable membrane 100, such as fiducials or other markers. Thematerial properties of the inflatable membrane 100 may be attributableto the combination of the matrix material 210, the pigment material 215and the fluorescent material 220.

The matrix material may include one or more polymer. The matrix material210, for example, may be a low-hardness (e.g., a low-durometer) liquidsilicone rubber, a liquid silicone elastomer, or a combination thereof.Exemplary silicones include silicones with the amount (e.g., mass) ofsilica used in production of the silicone reduced by a predeterminedamount, such as 1%, 2%, 5%, 10%, 20%, and/or other amounts as well. Insome implementations, more of one of the components of the matrixmaterial 210 may be used to modify the cross-linking density of thematrix material 210, reducing the silica concentration. The matrixmaterial 210 of the inflatable membrane 100 can also include silicaenriched silicone, latex, polyurethane, polyisoprene, engineeredthermoplastic polyurethane, thermoplastic polyethylene, plastisols, orany combination thereof. One or more thermoplastic elastomers may alsobe included in the matrix material 210. An example of a thermoplasticelastomer is MD-447, although other types of thermoplastic elastomersmay be used as well.

The pigment material 215, for opacity, may include any suitableparticulates, including suitable metals, metal oxides, metal carbides,and carbon blacks. In some implementations, the pigment material 215 maybe a carbon black, such as a channel carbon black, a furnace carbonblack, a lampblack, a thermal carbon black, an acetylene carbon black,or any combination thereof. The pigment material 215 may include primaryparticles, aggregates of primary particles, and agglomerates of primaryparticles. The primary particles can range in diameter from about 15 nmto about 20 nm. The aggregates can range in diameter from about 50 nm toabout 400 nm. Agglomerates of the primary particles can range indiameter from the size of aggregates up to 2 mm. In someimplementations, the primary particle size of the pigment material 215can range from about 10 to 30 nm, the size of aggregates of primaryparticles of pigment material 215 can range from about 50 to 200 nm, andaggregates of pigment material 215 may be up to 2 mm in diameter.High-purity furnace carbon black can have total polycylic aromatichydrocarbons (PAHs) at a level not exceeding about 0.5 parts per million(ppm) and benzo[a]pyrene not exceeding about 5.0 parts per billion(ppb).

The fluorescent material 220 of the inflatable membrane 100 may be of asingle type of fluorescent dye or a combination of fluorescent dyes. Anyfluorescent material 220, such as dye or pigment, or combination offluorescent material 220 with a large Stoke's shift and a broad emissionspectrum with at least two bandwidths that are suitable to use as signalin the 3D scanning system can be used in the inflatable membrane 100with the differentially absorbing medium 150. In some implementations,the fluorescent material 220 of an inflatable membrane 100 can be afluorescent dye that has reduced or negligible reflectance at thewavelengths which a 3D scanning system uses as signal. In otherimplementations, the inflatable membrane 100 may contain a concentrationof fluorescent material 220 high enough to obtain good signal, but lowenough for any reflection from the fluorescent material to be ignored.For example, for a 3D scanning system that measures the relativeintensities of red and green light, the ideal fluorescent material 220may be a dye that absorbs at higher energy wavelengths, such as blue orUV; a dye that fluoresces light that includes red and green wavelengths;and a dye that is used at a concentration such that the dye reflectslittle to no red or green light. Such a dye may be consideredtransparent to the wavelengths of light selected by the system, or auser, as the signal wavelengths. In this case, a dye that is excited byblue light, fluoresces yellow light (that includes red and green lightin its emission spectrum), and is transparent to red and green light isan ideal, invisible fluorescent dye. The dye is invisible in that itdoes not contribute substantially to the signal noise because it doesnot reflect, scatter, or otherwise perturb the fluoresced light at thewavelengths of interest, namely the red and green wavelengths. The dyemay be invisible also if it is used at a concentration where anyreflectance or scattering is negligible at the wavelengths of interest.This fluorescent dye may comprise a metal complex with a melting pointof around 350-356° C., and may be excited by light with any light in arange from UV to blue, such as light with a wavelength of about 366 nm,and which has an emission spectra with a peak at a wavelength of 549 nm.The dye may be a yellow powder when not mixed with a matrix material 215and has a particle size distribution, based upon the particle diameter,ranging from about 2.0 microns to about 20 microns. The particles usedin any of the materials herein may be rod shaped (e.g., high aspectratio particles) with a diameter of about 2 microns and a length ofabout 20 microns. An invisible, or transparent, fluorescent dye used asthe fluorescent material 220 in an inflatable membrane 100 can be ametal complex, an organic molecule, or any other material with suitableexcitation, emission (i.e., fluorescent), and reflective and scatteringproperties.

FIG. 3 is a diagram illustrating an exemplary process of forming theinflatable membrane 100 around a casting plate 310, in accordance withcertain aspects of the present disclosure. In an implementation, asshown at 320, a transferrable material may be applied to an outersurface of a casting plate 310 to form a pattern on the outer surface ofthe casting plate 310. The transferrable material may be transferredfrom the casting plate 310 to the inner surface of the inflatablemembrane 100. The transferring mechanism may be similar to ink beingtransferred from one surface to another, a chemical bonding process suchas an adhesion of some of the transferrable material to the inflatablemembrane 100, or the like. The transferrable material may include thepigment material 215 or any other type of dye, ink, or other material toform the pattern.

Once transferred, the transferrable material may form a pattern on theinner surface of the inflatable membrane 100. The round and/or sphericalcharacter of the transferrable material and the specific pattern shownin FIG. 3 is merely an example or for illustrative purposes and notintended to be limiting. Other patterns may include, for example, grids,circles, geometric patterns (hexagonal, octagonal, etc.), variations incolor, variations in intensity, or other types of spatially varyingpatterns.

The casting plate 310 may include, for example, a mandrel or otherobject that the inflatable membrane 100 may be formed around. In someimplementations, the casting pate 310 (or mandrel) may have an outershape that is generally elongate and may generally conform to a cavitycorresponding to an interior of an ear. The degree of conformity canvary between, for example, a conical shape (as shown in FIG. 4, below),a cylindrical shape, or a shape that may generally conform to featuresof a typical person's inner ear.

After the pattern has been cured, a composite material 350 may beapplied, at 320, to the outer surface of the casting plate 310, afterthe applying of the transferrable material, to form an inflatablemembrane 100. The composite material 350 may cover at least a portion ofthe pattern and include the florescent material 220, the pigmentmaterial 215, or both. In other implementations, the composite materialmay include other materials.

At 330, the inflatable membrane 100 may be cured to allow removal of theinflatable membrane 100 from the casting plate 310. Once removed, theinflatable membrane 100 may include an inner surface having the pattern.As discussed above, the pattern may be detectable upon receiving lightthat causes the fluorescing material 220 to emit fluoresced light 130.

FIG. 4 illustrates applying a transferrable material to an outer surfaceof a casting plate 310 to form a pattern, in accordance with certainaspects of the present disclosure. In some implementations, thetransferrable material may be applied by at least one of a hypodermicneedle, painting with a brush, spraying, printing from a laser jetprinter, printing from a pad printer, etching, and dipping. FIG. 4illustrates a hypodermic needle being used for this process.

FIG. 5 illustrates applying a composite material 350 to the outersurface of the casting plate 310 after the applying of the transferrablematerial, in accordance with certain aspects of the present disclosure.The composite material 350 may be applied by dipping the casting plate310 with the transferrable material into the composite material 350. Anyof the composite material 350, matrix material 210, pigment material215, and fluorescent material 220, may be contained in a dippingcontainer or other material dispenser.

In some implementations, there may be a window on formed on an end ofinflatable membrane 100. The window may be an aperture or may be anothermaterial, for example transparent plastic, that allows the transmissionof light through a distal end of the inflatable membrane 100. In someimplementations, the distal end may be the end of the inflatablemembrane that is inserted furthest into the ear of a person. The window,or an aperture configured to accept a window, may be formed by not fullydipping or coating the casting plate 310 with the composite material350. In this way, the aperture can be formed by selectively applying anyof the layers to the outer surface of the casting plate 310, withoutapplying any of the layers to the distal end of the casting plate. Inother implementations, the window may be formed by removing material,for example by cutting, from the end of a fully coated casting plate 310(as shown in FIG. 6). A transparent material, for example plastic orglass, can be applied to the distal end of the inflatable membrane 100to span the aperture and form the window.

When inserting the inflatable membrane into a cavity (for example in anear or other type of cavity), a user can insert the inflatable membrane100 using the window as a guide to avoid unwanted contact with interiorstructures or surfaces in the cavity. A detector (which may be the sameas the detector used to detect reflected or fluoresced light) can imagethe interior of the conforming membrane through the window while theinflatable membrane 100 is being inserted or otherwise used. In someimplementations, the imaging may occur through the absorbing mediumincluding inside the inflatable membrane.

FIG. 6 illustrates forming of the inflatable membrane 100 after removalfrom the composite material 350, in accordance with certain aspects ofthe present disclosure. After removal, the inflatable membrane 100 maybe cured, for example by drying in air, with heat, with cooling, or thelike. Once cured, the inflatable membrane 100 may be removed from thecasting plate 310.

FIG. 7 illustrates an exemplary inflatable membrane 100 after inversion,showing the pattern on the inner surface of the inflatable membrane 100,in accordance with certain aspects of the present disclosure. As shownin FIG. 7, under light that may cause the inflatable membrane 100 tofluoresce, the transferrable material (which is shown not fluorescing)may provide a measurable contrast that can be imaged by the detector.The images may be analyzed by an image analysis program to determine theinterior shape of the cavity 105.

FIG. 8 is a diagram illustrating a second exemplary process of formingthe inflatable membrane 100 around a casting plate 310, in accordancewith certain aspects of the present disclosure.

At 810, a first layer 805 of a fiducial material may be applied to anouter surface of a casting plate 310. The fiducial material may includefiducial markers suspended in the fiducial material. Fiducial markersmay be similar to the transferrable material in that because of the waythey block light from the fluorescent material, the fiducial markersthemselves may form a random pattern that can be imaged. The fiducialmarkers can include, for example, grains, shards, fragments, or othersmall objects (e.g., 50-400 microns, although other size may be used aswell). In some example embodiments, if the fiducial marker particle sizeis below 50 microns, the markers may be too small to be resolved by someimaging systems and/or may not provide sufficient contrast for theimaging system to identify a pattern. And, if the fiducial markerparticle size is above 400 microns, the markers may be too large andthus obscure the fluorescent signal behind the fiducial layer. Featuresof the suspended fiducial material may be interpreted as a randompattern by the detector. For example, the density, orientation,appearance, or the like, can define a random pattern. As one example, afiducial material having fiducial markers at a uniform densitythroughout the fiducial material can conform to an unperturbed state ofthe inflatable membrane 100. Where, for example, the inflatable membrane100 is stretched, the local area density of the fiducial markers maydecrease, indicating a deformation of the inflatable membrane 100.Similar changes to the random pattern (whether from the fiducial markersor the transferrable material) can indicate compression or a particularlocal surface orientation of the inflatable membrane 100.

The inflatable membrane 100 can also include, at any of the layersdescribed herein or formed by the fiducial material, a texture that canbe imaged (via differential absorption as noted) to enable theidentification of the shape of the inner surface of the inflatablemembrane 100. As noted, the pattern may be used to enable combing, orstitching, adjacent surface patches of imaging. The texture can include,for example, groves, etched channels, or grooves filled with anothermaterial of a different color, fluorescent property, surface texture, orthe like. The texture can be formed as a random pattern, a grid, a gridof varying shape, or the like to provide a surface with reference pointsthat can be imaged by a detector to determine the contours or shape ofthe interior or exterior surface of the inflatable membrane 100.

At 820, a second layer 815 of a composite material 350 may be applied tothe first layer to form an inflatable membrane 100. The compositematerial 350 may include a florescent material 220 and a pigmentmaterial 215.

In other implementations, at 830, a third layer 825 may be applied tothe second layer 815. The third layer 825 may include the pigmentmaterial 215 and not include the fluorescent material 220. In someimplementations, the third layer 825 includes only the pigment material220. In other implementations, there may be other materials besides thepigment material 220, except for the fluorescent material 215.

At 840, the inflatable membrane 100 may be cured to allow removal of theinflatable membrane 100 from the casting plate 310. Here, the inflatablemembrane 100 may include an inner surface having the fiducial markersdetectable upon receiving of light causing the fluorescing material toemit florescent light.

Similar to the method shown in FIG. 5 and FIG. 6, the first layer 805,the second layer 815, or the third layer 825 may be applied by dippingthe casting plate 310 into the fiducial material, the compositematerial, or the pigment material.

The combining and processing of the raw materials of the inflatablemembrane 100 may correlate strongly to the physical and opticalproperties of the finished inflatable membrane 100 used in a 3D scanningsystem. Fabrication methods that can be used to make inflatablemembranes are described below. Variation of the ratio of the constituentmaterials of the inflatable membrane 100 may cause variation in theperformance of the inflatable membrane 100, and such variations in rawmaterials will be described first. Then, various ways of mixing the rawmaterials will be described.

The raw materials for fabricating an inflatable membrane 100 can includethe matrix material 210, the pigment material 215, and the fluorescentmaterial, as described above. The raw materials can be combined byweight in the following ratios, in which the first number in the ratiois the weight of the raw material (e.g., pigment material 215 orfluorescent material 220) and the second number is the weight of thematrix material 210 in the mixture. In some implementations, aninflatable membrane 100 can include about 1:400 by weight of pigmentmaterial 215 for opacity and about 1:50 by weight of fluorescentmaterial 220. Alternatively or additionally, an inflatable membrane 100may include pigment material 215 by weight in an amount ranging fromabout 1:350 to about 1:450 and fluorescent material 220 by weight in anamount ranging from about 1:100 to about 1:25.

In some implementations, a mixture called a masterbatch, that is used tofabricate an inflatable membrane 100, can be created. The masterbatchmixture can be a small volume of material, such as about 10 g, thatincludes, for example, about 0.09±0.01 g of pigment material 215, about0.73±0.01 g of fluorescent dye, and about 9.17±0.02 g of matrixmaterial. In other implementations, the masterbatch mixture can be alarger volume of material, such as about 240 g, that includes about0.6±0.01 of pigment material 215, about 4.8±0;01 g fluorescent dye, andabout 120.0±0.02 g matrix material 210.

With respect to the florescent material, if the concentration is toolow, the intensity may not be bright enough to successfully image at adistance and make meaningful measurements. But if the concentration istoo high, there may be reflections which can confound the measurementsinside the membrane. With respect to the pigment material, if theconcentration is too low, the membrane may not be opaque enough andambient light from outside the membrane may introduce error into themeasurements (which may reduce the overall signal to noise ratio). Ifhowever the concentration is too high, the material may be too stiff andmay not conform to small features on the inner surface of the cavity(which may introduces error into the overall geometry computed by thescanning system).

In some such implementations, the matrix material 210 may be a two-partelastomer or polymer, and only one part may be added to the masterbatch.In other implementations, the matrix material 210 may not have more thanone portion, and part of the mass of the matrix material 210 may beadded to the masterbatch, and the rest of the matrix material 210 may becombined with the masterbatch following some processing.

Fabricating the masterbatch mixture can include some processing of thecombined matrix material 210. Such processing may include mixing inspeed mixer, milling in an attrition mill, ball milling, using mediawhile milling, mixing, or centrifuging the mixture. The media may beball milling media, such as ceramic or metal media. Ceramic media caninclude yttria stabilized zirconia pellets or balls, silica balls,alumina pellets or balls, or the like. Metal media can include stainlesssteel balls, aluminum balls, or metal balls of any metal or alloy thatis corrosion resistant and wear resistant in the presence of the matrixmaterial, pigment, and fluorescent material. Fabricating the masterbatchcan also include allowing the mixture to rest, or reduce in temperature,after mixing to an elevated temperature. The rest time can vary, and caninclude a time of at least about 30 seconds, at least about 60 seconds,at least about 90 seconds, and at least about 120 seconds. During therest time, the masterbatch mixture can be scraped down from the sides ofthe mixing container, as well as returning to ambient or near ambienttemperature.

During fabrication of the masterbatch mixture, as well as the finalmixture that is to become the inflatable membrane 100, a centrifuge setto various speeds of mixing can be used, with speeds ranging from about1500 revolutions per minute (RPM) to about 3000 RPM, including fromabout 2000 RPM to about 2500 RPM. Also, various sizes of milling ormixing media can be used, of the material and shape described above, andthe number of media can also be varied.

After the final mixture that is to become the inflatable membrane 100 iscreated, the mixture may be cured, molded, or dip-coated into sheets orother suitable shapes for the inflatable membrane 100. Curing theinflatable membrane 100 can include casting the membrane onto metalsheets, such as aluminum sheets, heating the cast material, or simplyaging the material, such as by allowing it to sit, for an extendedperiod of time.

In implementations involving dipping, solvents may be used dissolve theraw materials into solution. The amount and type of solvent may affectthe viscosity of the solution. The viscosity of the solution coupledwith the speed of insertion and removal from the dipping bath maydetermine the thickness of the dipped layer. Once dipped, the solventmay evaporates as the material cures.

FIG. 9 illustrates a process flow diagram for a representative method ofmaking inflatable membrane material, in accordance with certain aspectsof the present disclosure.

The first layer of material applied to the outer surface of the castingplate is a transferable layer. The transferable layer can be discrete,discontinuous or contiguous across the entire castable region of theouter surface of the casting plate. For example, the transferable layermay be a single region or marker that covers only a region of the outersurface of the casting plate. Alternatively or additionally, thetransferable layer may be discontinuous so that it forms a pattern ofsome kind with multiple discrete points where the pattern covers someportion of the casting surface. Alternatively or additionally, thetransferable layer may be contiguous so that it spans the entirecastable area of the casting plate with no voids or gaps in coverage.

As the amount of the constituent materials may be important to the finalmaterials characteristics, the first step may be to carefully weigh outpredetermined amounts of the matrix material 210, pigment material 215,and fluorescent material 220 into a mixing container, as in 910. Thematerial weighed out typically is for the creation of a masterbatchmixture, and it is mixed accordingly, 920. The mixing protocol forcreating a masterbatch can include using a centrifuge, such as a dualasymmetric centrifuge, to initially spin the material in the mixingcontainer for a predetermined time at a predetermined speed, such as forabout 60 seconds at 2500 revolutions per minute (RPM). The protocol maythen specify for the scraping of the material down from the sides of themixing container and to add mixing or milling media, such as about tenceramic cylinders (e.g., 10 millimeter cylinders), and then to spin thematerial in the mixing container for a predetermined time at apredetermined speed, such as for about 60 seconds at about 2100 RPM.After mixing, the masterbatch mixture may be allowed to rest, or cool,for a predetermined amount of time, such as two minutes. Then the sidesof the mixing container may be scraped down before repeating of thespinning of the mixing container. The resting, scraping, and spinningmay be repeated a set number of times for each process or untilachieving a desired consistency. As needed, the protocol to produce amasterbatch mixture may be repeated to create a desired volume or massof material for any number of inflatable membranes 100.

Once the masterbatch mixture is made, 920, more matrix material may bemixed with the masterbatch mixture to arrive at the final ratio of theconstituent materials, 930. This may be about a 1:1 mixture of themasterbatch mixture and pure matrix material, or it can be a differentratio of masterbatch mixture to pure matrix material. In someimplementations, the matrix material may have two components, one ofwhich may be mixed with the masterbatch mixture, while the othercomponent may be mixed in later to arrive at the final ratios of theconstituents. In some implementations, the masterbatch and pure matrixmaterial 210, or masterbatch and second component of the matrix material210, may not be mixed until right before the membrane is ready to beformed. Alternatively, or additionally, the masterbatch and matrixmaterial may be mixed using a mixing apparatus, such as centrifuge, aswell as mixing or milling media to create a mixture that eventuallybecomes the inflatable membrane 100 material, as in box 930.

In some implementations, casting plates 310 may be used to form and curethe inflatable membrane 100. The casting plates 310 may be prepared, asin box 940. The casting plates 310 may be ceramic, metal, polymer or anysuitable combination thereof, and preparation may include cleaning theplates with soap and water, with organic solvents, with mild acid, or acombination thereof. At 940, after cleaning, the casting plates 310 maybe treated with a surface treatment, such as applying a mold releaseagent or other surface treatment to facilitate removal of the inflatablemembrane from the casting plate 310. At 950, a transferrable materialmay be applied to an outer surface of a casting plate 310 to form apattern on the outer surface of the casting plate 310. At 960, after theapplying of the fiducial layer and allowing it to cure, a compositematerial may be applied to the outer surface of the casting plate 310 toform an inflatable membrane 100. The composite material may cover atleast a portion of the pattern and comprising a florescent material anda pigment material. At 970, the inflatable membrane may be cured toallow removal of the inflatable membrane 100 from the casting plate 310.The inflatable membrane 100 may include an inner surface having thepattern detectable upon receiving of light causing the fluorescingmaterial to emit florescent light.

Alternatively or additionally, the casting plates 310 may be attached toan apparatus that allows for the simultaneous application of the castingplates 310 and conveyance of the spreadable membrane material along apath. Such conveyance can also include the application of heat or othermodifications to the environment, such as relative humidity, by amembrane curing or fabricating facility or system. The application ofheat or adjustment of the environment may facilitate curing of theinflatable membrane 100. The cured membrane material may be removed fromthe casting plates 310, and the membrane material may be stored or sentto another facility for further processing. Further processing mayinclude the application of more fluorescent material to create fiducialmarkings, cutting and joining the membrane material to create aninflatable membrane 100 sized appropriately for an intended use,assembly into a system, and the like. Although the previous examplesreferred to specific times, sizes, ratios, speeds (e.g., RPM), othervalues may be implemented as well.

Any of the features described herein, for example the process describedabove with regard to FIG. 9, may be performed under the control of, orassisted by, one or more computer processors.

Although a few embodiments have been described in detail above, othermodifications are possible. For example, the method steps depicted inFIGS. 3, 8, 9, and described herein do not require the particular ordershown, or sequential order, to achieve desirable results.

FIG. 10 illustrates a simplified diagram imaging the interior surface ofthe inflatable membrane 100 through a media that differentially absorbsdifferent wavelengths to determine the shape of an exterior surface ofan object 1010, in accordance with certain aspects of the presentdisclosure. In some implementations, the inflatable membrane 100described herein can be used to also determine the surface shape orfeatures of an object 1010 that is not a cavity. For example, as shownin FIG. 10, an object can be placed or otherwise brought into contactwith the inflatable membrane 100, optionally resting on a surface 1020.This can cause the inflatable membrane 100 to conform to an exteriorsurface of the object, as opposed to an interior surface of a cavity.The light source 115 (which may also include a detector) may imagereflected or fluoresced light from the interior surface of theinflatable membrane 100. The distorted surface of the inflatablemembrane can then be analyzed to determine the exterior shape of theobject 1010.

As described above with reference to FIG. 1, the inflatable memberane100 can include a medium 150 that differentially attenuates light (froma light source 115 or from a fluorescent portion of the inflatablemembrane 100). As the light attenuates there may be a first intensity oflight 1030 that is strongly attenuated and a second intensity of light1040 that is attenuated less than the first intensity of light 1030. Themeasured intensities may be compared to determine the shape of theinterior surface of the inflatable membrane 115 and hence the shape ofthe exterior surface of the object 1010.

Applications of this implementation can include measuring the surfacefeatures of the external ear features or other facial features, a handpressing on the inflatable membrane 100, a foot standing on theinflatable membrane 100, or the like. The object 1010 can also includeany sort inanimate object that is positioned to deform the inflatablemembrane 100 as described herein. As in other implementations, theinflatable membrane 100 can be filled with a fluid to provide a desiredpressure or to facilitate transmission of light to the detector forimaging. Additionally, the external surface being scanned could exist inan environment where a vacuum or otherwise reduced pressure could beapplied to create an increased pressure differential across the surfaceof the inflatable membrane 100 improving conformance of the inflatablemembrane 100 to the higher resolution features on the surface beinginspected or analyzed.

To provide for interaction with a user, one or more aspects or featuresof the subject matter described herein (for example, to mix or control aprocess as described above with regard to FIG. 9, as well as otheraspects disclosed herein) can be implemented on a computer having adisplay device, such as for example a cathode ray tube (CRT) or a liquidcrystal display (LCD) or a light emitting diode (LED) monitor fordisplaying information to the user and a keyboard and a pointing device,such as for example a mouse or a trackball, by which the user mayprovide input to the computer. Other kinds of devices can be used toprovide for interaction with a user as well. For example, feedbackprovided to the user can be any form of sensory feedback, such as forexample visual feedback, auditory feedback, or tactile feedback; andinput from the user may be received in any form, including, but notlimited to, acoustic, speech, or tactile input. Other possible inputdevices include, but are not limited to, touch screens or othertouch-sensitive devices such as single or multi-point resistive orcapacitive trackpads, voice recognition hardware and software, opticalscanners, optical pointers, digital image capture devices and associatedinterpretation software, and the like.

In the descriptions above and in the claims, phrases such as “at leastone of” or “one or more of” may occur followed by a conjunctive list ofelements or features. The term “and/or” may also occur in a list of twoor more elements or features. Unless otherwise implicitly or explicitlycontradicted by the context in which it used, such a phrase is intendedto mean any of the listed elements or features individually or any ofthe recited elements or features in combination with any of the otherrecited elements or features. For example, the phrases “at least one ofA and B;” “one or more of A and B;” and “A and/or B” are each intendedto mean “A alone, B alone, or A and B together.” A similarinterpretation is also intended for lists including three or more items.For example, the phrases “at least one of A, B, and C;” “one or more ofA, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, Balone, C alone, A and B together, A and C together, B and C together, orA and B and C together.” Use of the term “based on,” above and in theclaims is intended to mean, “based at least in part on,” such that anunrecited feature or element is also permissible.

The subject matter described herein can be embodied in systems,apparatus, methods, computer programs and/or articles depending on thedesired configuration. Any methods or the logic flows depicted in theaccompanying figures and/or described herein do not necessarily requirethe particular order shown, or sequential order, to achieve desirableresults. The implementations set forth in the foregoing description donot represent all implementations consistent with the subject matterdescribed herein. Instead, they are merely some examples consistent withaspects related to the described subject matter. Although a fewvariations have been described in detail above, other modifications oradditions are possible. In particular, further features and/orvariations can be provided in addition to those set forth herein. Theimplementations described above can be directed to various combinationsand subcombinations of the disclosed features and/or combinations andsubcombinations of further features noted above. Furthermore, abovedescribed advantages are not intended to limit the application of anyissued claims to processes and structures accomplishing any or all ofthe advantages.

What is claimed is:
 1. A method comprising: applying a transferrablematerial to an outer surface of a casting plate to form a pattern on theouter surface of the casting plate; applying, after the applying of thetransferrable material, a composite material to the outer surface of thecasting plate to form an inflatable membrane, the composite materialcovering at least a portion of the pattern and comprising a florescentmaterial and a pigment material; and curing the inflatable membrane toallow removal of the inflatable membrane from the casting plate, theinflatable membrane comprising an inner surface having the patterndetectable upon receiving of light causing the fluorescing material toemit florescent light.
 2. The method of claim 1, wherein thetransferrable material is applied by a hypodermic needle, painting witha brush, spraying, printing from a laser jet printer, printing from apad printer, and/or etching and dipping.
 3. The method of claim 1,wherein the composite material is applied by dipping the casting platewith the transferrable material into the composite material.
 4. A methodcomprising: applying a first layer of a fiducial material to an outersurface of a casting plate, the fiducial material comprising fiducialmarkers suspended in the fiducial material; applying a second layer of acomposite material to the first layer to form an inflatable membrane,the composite material comprising a florescent material and a pigmentmaterial; and curing the inflatable membrane to allow removal of theinflatable membrane from the casting plate, the inflatable membranecomprising an inner surface having the fiducial markers detectable uponreceiving of light causing the fluorescing material to emit florescentlight.
 5. The method of claim 4, wherein the fiducial markers have aparticle size of 50 microns to 400 microns.
 6. The method of claim 4,wherein the first layer is a clear layer without pigment material andthe florescent material, wherein the second layer includes thefluorescent material but not the pigment material, wherein the thirdlayer includes the pigment material but not the fluorescent material. 7.The method of claim 4, wherein the pigment material is selected to varythe optical and/or mechanical properties of the membrane.
 8. The methodof claim 6, wherein the first layer, the second layer, and the thirdlayer are applied by dipping the casting plate into the fiducialmaterial, the composite material, or the pigment material.
 9. The methodof claim 4, further comprising: forming an aperture in a distal end ofthe inflatable membrane; and applying a transparent material spanningthe aperture to form a window in the distal end of the inflatablemembrane.
 10. The method of claim 9, the forming comprising: selectivelyapplying the first layer and the second layer to the outer surface ofthe casting plate, without applying the first layer and the second layerto the distal end of the casting plate, to form the aperture in thedistal end.
 11. An apparatus comprising: an inflatable membranecomprising, a pattern layer, a fluorescent layer, and a window, thepattern layer comprising an inner surface and an outer surface, thepattern layer comprising a pattern on the inner surface of the patternlayer and at least a portion of the pattern layer formed by atransferrable material transferred from a casting plate to the innersurface; the fluorescent layer comprising an inner surface and an outersurface, the inner surface of the fluorescent layer abutting the outersurface of the pattern layer and comprising a fluorescent materialwhich, upon receiving of light, causes the florescent material to emitfluorescent light and causing the pattern to be detectable by adetector; and the window comprising a transparent material that spans anaperture formed in a distal end of the inflatable membrane.
 12. Theapparatus of claim 11, the fluorescent layer further comprising apigment material.
 13. The apparatus of claim 11, wherein the patterncomprises a grid formed by the transferrable material.
 14. The apparatusof claim 11, wherein the pattern comprise a plurality of spots formed bythe transferrable material.
 15. The apparatus of claim 11, furthercomprising: a pigmented layer having an inner surface and an outersurface, the inner surface of the pigmented layer abutting the outersurface of the fluorescent layer and comprising a pigment material. 16.The apparatus of claim 15, the fluorescent layer further comprising amatrix material that includes the fluorescent material and the pigmentmaterial.
 17. The apparatus of claim 11, wherein the inflatable membraneis generally conical in shape such that the inflatable membrane isinsertable into the ear of a person.
 18. The apparatus of claim 11,wherein the fluorescent material is a fluorescent dye and the pigmentmaterial is a carbon black.
 19. The apparatus of claim 11, furthercomprising: an aperture formed in a distal end of the inflatablemembrane; and a window comprising a transparent material spanning theaperture to allow light to pass through the distal end.
 20. An apparatuscomprising: an inflatable membrane comprising a pattern layer, afluorescent layer, and a window, the pattern layer comprising an innersurface and an outer surface, the pattern layer comprising a randompattern formed by fiducial markers suspended in a fiducial materialintegrated with the pattern layer and at least a portion of the patternlayer formed by a casting plate configured to create the fiducialmarkers; and the fluorescent layer comprising an inner surface and anouter surface, the inner surface of the fluorescent layer abutting theouter surface of the pattern layer and comprising a fluorescent materialwhich, upon receiving of light, causes the florescent material to emitfluorescent light and causing the pattern to be detectable by adetector; and the window comprising a transparent material that spans anaperture formed in a distal end of the inflatable membrane.
 21. Theapparatus of claim 20, further comprising a pigment layer having aninner surface and an outer surface, the inner surface of the pigmentlayer abutting the outer surface of the fluorescent layer, the pigmentlayer comprising a pigment material and not having the fluorescentmaterial.